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Compared with the general population, people with HIV are at elevated risk of lung cancer at younger ages and with less smoking experience, aidsmap reports. Consequently, researchers have advocated that the criteria in national lung cancer screening guidelines be expanded for the HIV population.

Presenting their findings at the 2019 Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle, researchers compared lung cancer screening guidelines used in the National Lung Screening Trial, which excluded those with HIV, with cases of such cancer among individuals living with the virus.

The United States Preventive Services Task Force (USPSTF), informed by the results of the National Lung Screening Trial, advises that people between 55 and 80 years old receive annual CT scans if they have smoked for a cumulative 30 years and if they smoke currently or quit doing so less than 15 years ago.

The researchers in this new study analyzed data on current or former smokers 40 years old or older who were members of the Women’s Interagency Study (WIHS) or the Multicenter AIDS Cohort Study (MACS). They found 44 women and 17 men who were diagnosed with lung cancer during the study period, for a diagnosis rate per cumulative 100,000 years of follow-up of 270 cases among women and 104 among men. These individuals were then matched with similar members of WIHS or MACS who had HIV but not lung cancer.

About 40 percent of women with or without lung cancer still smoked. Thirty percent of the women with lung cancer had smoked for at least 30 cumulative years, compared with 30 percent of the women without lung cancer. This difference was not statistically significant, meaning it could have been driven by chance. That said, the women with lung cancer who had quit had a nearly twofold greater likelihood, compared with those without cancer, of having done so 15 years or less prior to their diagnosis.

As for men, 71 percent of those with lung cancer and 24 percent of those without the disease still smoked and had at least a 30-year cumulative smoking history; this difference was statistically significant. Almost all the men who quite did so within 15 years.

Given these findings, the researchers concluded that just 16 percent of the women and 24 percent of the men with lung cancer would have been advised to receive annual CT scans to look for signs of the disease under the USPSTF guidelines.

Optimal lung cancer screening guidelines specific to the HIV population, the researchers concluded, would recommend annual CT screening for women starting at age 49 if they had smoked for a cumulative 16 years or more and had quit no more than 15 years prior. These guidelines would correctly identify lung cancer 52 percent of the time and would correctly identify the lack of such a cancer in 75 percent of cases. For men, screening should start when they hit 43 years old if they have smoked for a cumulative 19 years or more and have quit within 15 years. This would have an 82 percent success rate in identifying lung cancer cases and a 76 percent accuracy rate in diagnosing a lack of such a malignancy.